Voltage-regulator.



R. P. JACKSON.

VOLTAGE REGULATOR. APPLIoAfrIoN FILED MAR. e, 190s.

Patented Feb. 20, 1912. V

2 SHEETS-SHEET 2.v

3g I A A. /33

WITNESSES: INV NTOR` v i vAT'TORNEY UNITED STATES PATENT OFFICE.

RAY P. JACKSON, OF WILKINSBURG, PENNSYLVANIA, ASSIGNOR, BY MESNE ASSIGN-4 IVILENLS,l T0 WESTINGHOUSE ELECTRIC & MANUFACTURING COMPANY,'OF EASTPITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

VOLTAGE-REGULATOR.

l Specification of Lettersv Patent. Y Patented Feb. 20, 1912.

Application filed March 9, 1908. Serial No. 420,065. i

To all whom it may concern:

Be it known that I, RAY P. JAcKsoN, a citizen of the United States, anda resident l of lVilkinsburgin the county of Allegheny nomical inconstruction, and in which no movable' contacts or other members shallbe employed.

My invention consists in employing a current-rectifying device totransform the alternating current of the distributing circuit intodirect current to be sup-plied to a circuit including' either the fieldmagnet winding of the main generator or that of an exciter for the maingenerator. A suitable ohmic resistance is connected between the directcurrent terminals of the rectifying device and also in series with thefield -niagnet Winding upon which the regulation is directly effected.The rectifying device being connected across the distributing cir cuit,a direct current voltage is applied to the resistance which issubstantially proportional to the voltage bf the alternating currentcircuit, and, since the field magnet winding is either shunt orseparately excited, the drop of'potential over the field magnet windingis caused to vary substantially inversely as the voltage of thedistributing circuit. Thus, when the voltage of the distributing circuitdecreases, the cur.- rent traversing tlieffield magnet windingincreases, thereby serving to increase the voltage of the generator,while, when the voltage of the circuit increases, the field strength iscaused to decrease with a corresponding diminution of the generatorvoltage.

Figure 1 of the accompanying drawings is a diagrammatic View of asystemeinboely;`v`

ing my invention, and Figs. 2 and 3 are similar views of modificationsof the system ofFigzl.` l l "t,"

In Fig. 1, a two-phase distributing circuit comprising condiictors 1, 2,3 and 4 is supplied from a generator 5 having a field magnet winding 6that is' supplied from an exciting generator 7, field magnet winding 8of which lis here shown as shunt excited in the usual manner, though, ofcourse, it may be otherwise excited, if desired. In

'series with they exciter field magnet wind.

ing 8 is anfoliniic resistance 9 upon which a direct current voltagethat is proportional to the alternating voltage of the distributingcircuitis impressedby means of a current-rectifying apparatus comprisinga rectifying device 10 and a transformer 11, the primary Winding 12 ofwhich is connected between circuit conductors 2 and 4.-. The rectifyingdevice l0 is here indicated asl of the `vapor type, though any othersuit-able device may be employed instead, provided the' drop ofpotential through the rectifier,- ,or the ratio of the alternating tothe direct current voltage, is substantially constant for all currentvalues within the range of operation. minal 13 of the rectifyingA device10 is connected to one terminalof the resistance 9,

and the other terminal of the resistance is' connected to a neutral orother suitable intermediate point 14 of the secondary winding 15 of thetransformer 11,' the extremities of the winding 15 being connected,respectively, to alternating current terminals 16 and 17 of theyrectifying device.` The trans-l former 11 is provided withari-auxiliary -rent terminal of the rectifying device, an

impedance device 21 being included in the lat-ter connection for thepurpose `of sus- The positive or direct current tertaining therectifiedcurrent and of affording the desired regulation. Thetransformer winding 18 and the auxiliary terminals 19 and 20 of therectifying device are employed for the purpose of maintaining therectifying deviceinactive operation, regardless of whether. or notcurrent traverses the dewvic'e'y way ofy the -main terminals. 'An

impedance device 22 isicledin-'the con-Y` nection between .the positiveterminal 13 of v Vthe rectifyling device and the resistance `9 for thepurpose of sustaining the rectified current and ofaifording suitableregulation.

Under normal operating conditions, the voltage applied to the resistance9 bythe rectifying device will be in the same direction asthat appliedthereto by the exciter 5, armature and will just equal the drop ofpotential over the resistance which is caused by the normal flow ofcurrent from the exciter armature. If, however, the voltage of thecircuit 1-2-3-4 decreases, the voltage applied across the terminals ofthe resistance 9 by the rectifying devicelwill be correspondinglydiminished, while the drop of potent-ial over the field magnet winding 8will be correspondingly increased. The conditions'just stated will bebetter understood by assuming that the resistances of the field magnetwinding 8 and of the del" -vice 9 are each 5 ohms, and'that, undernormal conditions, the voltage -of the exciter is 100. Then the drop ofpotential over the field magnet winding, as well as'that vover theresistance 9, is 50 volts and the rectifying device should apply 50volts to the terminals of the resistance device. lf the volt- 'age ofthe circuit 1--2--3--4` decreases to such an extent that the voltageapplied by the'rectifying device to the resistance 9 1s.

reduced to 45, the drop of vpotential over the field magnet windingbecomes 55 volts,

Sowith the result that 11 amperes of current are caused /to' traversethe field magnet winding, whereas, under normal conditions, only '10amperes traverse the said winding. The field strength of the exciter iscorrespondingly increased, and in like 'mannen also, the field strengthand voltage of the main generator. y If the voltage of the distributingcircuit increases to suchan extent that the rectifying device is causedto apply 55 volts to the resistance 9, a drop of potential of 45 voltswill occur over the field .magnet winding, with the result that only'9amperes of vcurrent will traverse the saidl winding. The voltage of theexciter, and

main generator will, therefore, be correspondingly reduced. Under otherconditions than thosespecifically described, the operation of theregulator will be readily understood from the foregoing description.vVlhile, in most cases, it will be found preferable to adjust the fieldstrength of the main generator indirectly by adjusting 'the fieldstrength of the exciter, it may 'be -found desirable, in some cases, toeffect the regulation directly upon the main generator, as illustratedin Fig. 2, in which a resistance 25 is connected in series with fieldmagnetwinding 26 of the main generator;c

the resistance 25 and the field magnet winding 26 being included in thearmature circuit ofa direct current exciter 27. As illus-l trated inFig.- 1, the resistance device 25 is a. connected between the directcurrent termi- 6" nals' of the rectifying apparatus, and the also thefield strength and voltage of they noifaevo operation of the system issubstantially as described in connection with Fig. l.

lne, order that the regulator may act promptly in restoring normalvoltage conditions, and in order to prevent undue oscillations in thegenerator voltage during the regulating action, it may be founddesirable to arrange the apparatus as illustrated in Fig. 3, in which arectifying device 28 is provided with an auxiliary terminal 29 that '75is connected to one extremity of field magnet Winding 30 of the exciter,the other extremityof the field magnet winding being connected to thepositive or direct current terminal 3l' of the rectifying device. The 80neutral or some o therv suitable intermediate point of the secondarywinding 32 of a transformer 33 is connected to one extremity of aresistance 34 that is included in series circuit with the exciter fieldmagnet winding 80.`

In general, the operation of the system is similar to that of Fig. l,except that when the drop of potential'over the field magnet winding l80reaches a predetermined value, an arc occurs between terminals 29 and 31of the rectifying device 28, the greater por` tion ofthe current beingthereby diverted from the field magnet winding 30. Upon establishment ofthe arc, a'considerable reduction'i'n the voltage between the terminals29 and 31 of the rectifying device occurs, the voltage ultimatelybecoming insuliicient to maintain the arc, whereupon the field strengthof the exciter will be again increased. Thus, the field strength of theexciter is prevented from continuing to increase to such a value as tocause the voltage of the main generator to increase beyond its normalvalue, as might otherwise the 1015 case. n

By the proper adjustment of the apparat-us, oscillations of the maingenerator voltage from its normal value, in effecting the desiredregulation, may be greatly re- 1105l .main generator voltage will beaffected by substantially the average of the said oscillations.

I claim as my invention:

l. The combination with an electrical circuit, and a generatorassociated therewith, of means for governing thevoltage of the .sistanceto -for causing resistance to vary approximately as .the

generator comprising a field magnet winding, a resistance in seriestherewith, and a current-rectifying device having its directcurrentterminals respectively connected to the terminals of the resistance and-adapted to cause the drop of potential over the resistance to Varyapproximately as the Voltage of the circuit.

2. The combination with an electrical circuit, and a generatorassociated therewith, of means for governing the volt-age of thegenerator comprising a field magnet winding,a resistance in seriestherewith, and a current-rectifying device adapted to cause the dropofpotential over the revary approximately as the voltage of the circuit,and having auxiliary terminals connected respectively to points of thefield magnet winding.

The combination with an electrical circuit, and a generator associatedtherewith,

of means for governing the voltage of the generator comprising a ieldmagnet winding, a resistance in series therewith, means the drop ofpotential over the voltage of the circuit, and means for causing areduction in the drop of potential over the field magnet winding whenthe said drop attains a predetermined value.

4t. The combination with an electrical c ircuit, and a generator'associated therewith, of a currrent-rectifying device upon which isimpressed a voltage that isA proportional to the voltage of Saidcircuit, an exciter for the generator having a ield magnet winding, anda resistance connected in series with the exciter field magnet windingand between the direct current terminals of the rectifying device.

5. The combination with an electrical circuit and a generator associatedtherewith, of means for governing the voltage 'of the generatorcomprising a field magnet winding, a resistancel in series therewith,and a current-rectifying device upon which a voltage s impressed that isin proportion to the voltage of the current terminals of which arerespectively connected to the terminals of the resistance.

6'. The combination with an electrical circuit and a generatorassociated therewith, of means for governing the voltage of thegenerator comprising a field magnet winding, a resistance in'seriestherewith, and means for causing the drop of potential over theresistance to v'ary approximately as the voltage of the circuit.

In testimony whereof, I have hereunto subscribed my name this 27th dayof Feb., 1908.

R. B. INGRAM, lBIRNEY lHiiviizs.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

said circuit and the direct V

